II. GENERAL HISTORICAL SUMMARY. 



An attempt has been made to render available to the investigator all the 

 literature which deals directly with succession. The abstracts of the many- 

 books and papers have been grouped in accordance with climax areas, and 

 will be found in Chapters X and XI. A nvunber of them have been quoted 

 only in the text of the following chapters, however. Those upon the various 

 horizons of peat-beds are grouped in Chapter XIII, in connection with the 

 discussion of coseres and cliseres. For convenience of reference, the page of 

 the abstract or quotation is indicated in the bibliography at the end of the 

 book. In order to give students a general idea of the development of the 

 subject, an account of all the earlier papers accessible is given here. After 

 the work of Hult (1885), studies of succession became more frequent. In this 

 recent period, those works have been selected which mark an advance in the 

 principles or methods used in the investigation of development, or which 

 endeavor to organize the field in some degree. The literature of the peat 

 cosere is so vast, however, that only a few of the more comprehensive 

 works can be mentioned here. This applies especially to the literature of 

 Quaternary and earlier plant horizons, much of which has only an indirect 

 bearing upon the problems of succession. This field has also produced a rich 

 harvest of polemic writings, nearly all of which are ignored, with the exception 

 that many of the titles are listed in the bibliography. 



EARLY INVESTIGATIONS. 



King, 1686. — ^While there is abundant evidence that succession in moors 

 and in forest burns had been a matter of observation and comment for many 

 centuries, the earliest recorded work that approaches investigation in its 

 nature was that of King (1685: 950) on the bogs and loughs of Ireland. The 

 following excerpts indicate the degree to which he understood the nature and 

 origin of bogs: 



"Ireland abounds in springs. Grass and weeds grow rapidly at the out- 

 burst of these. In winter, these springs swell and loosen all the earth about 

 them ; the sward, consisting of the roots of grasses, is thus lifted up by the water. 

 This sward grows thicker and thicker, till at last it forms a quaMng bog. . . . 

 I am almost (from some observations) tempted to believe that the seed of this 

 bog moss, when it falls on dry and parched ground begets the heath. . . . 

 It is to be observed that the bottom of bogs is generally a kind of white clay 

 or rather sandy marl, and that bogs are generally h^her than the land about 

 them, and highest in the middle. . . . The true origin of bogs is that those 

 hills that have springs and want culture constantly have them: wherever they 

 are, there are great springs. 



"I must confess there are quaking bogs caused otherwise. When a stream 

 or spring runs through a flat, if the passage be not tended, it fills with weeds 

 in summer, trees fall across it and dam it up. Then, in winter, the water 

 stagnates farther and farther every year, till the whole flat be covered. Then 

 there grows up a coarse kind of grass peculiar to these bogs; this grass grows in 

 tufts and their roots consolidate together, and yearly grow higher, in so much 

 that I have seen of them to the height of a man. The grass rots in winter 

 and falls on the tufts, and the seed with it, which springs up next year, and 



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